Asymmetric Digital Subscriber Line.
As opposed to SDSL (Symmetric Digital Subscriber Line), an ADSL connection runs through an ordinary phone line and receives data over the internet at high speeds, comparable to those of cable modems, though it transmits data at only a fraction of the speed at which it receives data -- but still faster than a conventional 56Kbps modem.

User Datagram Protocol. An unreliable method of sending packets, UDP is faster but less stable in terms of reliable information than TCP. UDP is often used for faster transmission of data that is not useful at a later time.